Master of Science / Department of Biological & Agricultural Engineering / Naiqian Zhang / Permittivity is an important property of dielectric materials. By measuring the permittivity of a material, it is possible to obtain information about the material’s physical and chemical properties, which are of great importance to many applications. In this study, a realtime control system for a frequency-response (FR) permittivity sensor was developed. The core of the hardware was a kitCON167 microcontroller (PHYTEC America, LLC), which controlled and communicated with peripheral devices. The system consisted of circuits for waveform generation, signal conditioning, signal processing, data acquisition, data display, data storage, and temperature measurement. A C program was developed in the TASKING Embedded Development Environment (EDE) to control the system. The control system designed in this study embodied improvements over a previously designed version in the following aspects: 1) it used a printed circuit board (PCB); 2) the measurement frequency range was extended from 120 MHz to 400 MHz; 3) the resolution of measured FR data was improved by using programmable gain amplifiers; 4) a data storage module and a real-time temperature measurement module were added to the system; 5) an LCD display and a keypad were added to the system to display the FR data with corresponding frequencies and to allow users to enter commands. Impedance transformation models for the sensor probe, the coaxial cable that connects the control system with the sensor probe, and the signal processing circuit were studied in order to acquire information on the permittivity of measured materials from measured FR data. Coaxial cables of the same length terminated with different loads, including an open circuit, a short circuit, a 50 resistor, and a 50 resistor paralleled by a capacitor, were tested. The results indicated that the models were capable of predicting the impedances of these specific loads using the FR data. Sensor probes with different sizes and coaxial cables with two different lengths terminated with the same sensor probe were also tested. The results were discussed. Additional tests for the gain and phase detector were conducted to compare FR data measured by the gain and phase detector with those observed on an oscilloscope. The results were discussed.

Master of Science / Department of Agronomy / DeAnn Presley / Steve Thien / Interest and participation in urban agriculture is growing in many cities throughout the United States. Urban gardeners and farmers produce food on various types of urban lands. Common soil contaminants of urban areas limit the amount of land on which food may safely be grown. The objective of this study was to assess and meet the informational and technical assistance needs of urban gardeners and farmers as well as students enrolled in the introductory soils science course at Kansas State University on the topics of urban soil quality and contamination. A needs assessment survey of urban gardeners and farmers was conducted in four communities; Tacoma and Seattle, Washington, Kansas City, Kansas and Missouri, Manhattan, Kansas, and Gary, Indiana. The survey generated information about what urban gardeners and farmers know, think they know, and want to know about urban soil quality and contamination. Eighty-eight percent of respondents indicated that they do not have knowledge of the best management practices to minimize health risks involved when growing food crops on soils contaminated with lead, cadmium, arsenic or organic contaminants. Our results suggest that urban gardeners and farmers require and want information and guidance on soil testing for common contaminants, interpretation of testing results, and best management practices for growing food on mildly contaminated soils. The students enrolled in the introductory soil science course at Kansas State University are future agricultural and environmental professionals who need skills to address urban soils issues. Most of the students in the Agronomy 305: Soils course are not Agronomy majors. Furthermore, an increasing number of Agronomy 305 students come from urban and suburban communities and/or have interest in working in urban environments upon completion of their undergraduate degree. An urban soils laboratory was developed in response to the future workforce demands as well as the demographics of students enrolled in the Agronomy 305 course. Throughout the semester students evaluated the physical, chemical, and biological properties of a soil from this urban community garden. Reaction of students to the new urban soils lab offering has been positive with 72% of students enrolled in the course reporting that they have interest and need in learning about the urban soil issues covered in the lab course. Overall, student responses about their learning experience in the urban soils laboratory course were positive, indicating that incorporating urban soil principles enhanced their soil science education. Students who participated in the urban soils lab are better prepared, as future agricultural and environmental professionals, to address the educational and technical assistance needs of urban growers.

Master of Science / Department of Human Nutrition / Tonatiuh Melgarejo / Late-lactation Holstein cows (n=9/treatment) were used to evaluate effects of continuous adipose tissue TNFα administration on glucose and fatty acid (FA) metabolism. Cows were blocked by feed intake and milk yield and randomly assigned within block to control or TNFα treatments. Treatments (4 mL saline or 14 μg/kg TNFα in 4 mL saline) were infused continuously over 7 d via 2 osmotic pumps in the adipose layer in the tailhead region. Plasma, milk samples, milk yield, and dry matter intake (DMI) data were collected daily. On d 7, pumps were removed and liver and contralateral tailhead adipose biopsies were collected. Results were modeled with fixed effect of treatment and random effect of block; P values > 0.10 were considered non-significant. TNFα did not alter liver TNFα mRNA abundance, plasma TNFα, IL-4, IL-6, or interferon-γ concentrations, DMI, or rectal temperature. Milk fat and lactose concentrations decreased with TNFα (P < 0.05), but milk yield was unchanged and treatments did not alter the proportion of short vs. long-chain FA in milk on d 7. Treatments did not alter plasma NEFA concentration, liver triglyceride content, or adipose mRNA abundance for hormone-sensitive lipase or perilipin. Plasma glucose turnover rate, as measured by disappearance of U-13C-glucose bolus, was not altered by treatment, nor was liver mRNA abundance for phosphoenolpyruvate carboxykinase or pyruvate carboxylase. However, TNFα tended to decrease adipose TNFα mRNA abundance (P=0.09) and increase liver IL-10 mRNA abundance (P=0.05) compared to controls. Messenger RNA expression of IL-10 in adipose and IL-37 in liver tissue increased significantly in cows treated with TNFα (Figure 1; P = .02 adipose; P < 0.05 liver). This TNFα delivery protocol may have allowed for an adaptive anti-inflammatory response to suppress systemic inflammation, which may account for the lack of metabolic responses compared with previous responses to daily subcutaneous TNFα injections.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Kyle Douglas-Mankin / Soil erosion is one of the most important of today’s global environmental problems. Over the past few decades, soil conservation practices were implemented to reduce soil erosion in the United States. However, excessive sediment still remains among the most prevalent water quality problems. Agricultural fields and in particular ephemeral gullies (EGs) are considered to be a major contributor of sediment. The overall goal of this study was to improve modeling utility to identify and quantify sources of sediment. Specific objectives were: (1) to develop and demonstrate a method of field-scale targeting using Soil and Water Assessment Tool (SWAT) and to use this method as a targeted, flexible approach to pay explicitly for sediment-yield reductions; (2) to evaluate topographic index models (Slope Area [SA], Compound Topographic Index [CTI], Slope Area Power [SAP] and Wetness Topographic Index [WTI]) and a physical-based model (Overland Flow Turbulent [OFT]) in predicting spatial EG location and lengths. Black Kettle Creek watershed was the focus of an innovative project to pay for modeled field sediment reductions. An Arc-Geographical Information System (GIS) tool bar was developed that post processed SWAT hydrologic response unit output to field boundaries and prepared maps of high-priority fields by sediment, total nitrogen, and total phosphorus and was demonstrated to be useful for field-scale targeting. Calibrated SWAT model was used to establish baseline sediment yields. Various Best Management Practices (BMPs) were simulated and payments to implement each BMP for a given field were calculated. This study helped to guide determination of appropriate farmer support payments and quantified the important influence of BMP type and site-specific conditions for use in targeting conservation practice funding to achieve maximum soil-loss reductions per dollar spent. Extreme care should be used in selecting the source of spatial model input data when using SWAT for field-level targeting. Automated geospatial models were developed in a GIS environment to spatially locate and derive length of EGs using topographic index and physical based models. EG predictions were better for the SA model among the four topographic index models tested. Individual calibration of topographic index model threshold for each application site was needed. An OFT model (physical based model), which utilized topography, precipitation, soil, landuse/landcover and SWAT-based runoff estimates, did not need individual site calibration, and may have broader applicability than empirical based models.

Doctor of Philosophy / Department of Grain Science and Industry / Keith C. Behnke / A series of experiments was conducted to compare methods used to evaluate the durability of animal feed pellets, as well as to investigate the potential for modeling the effects of formulation and processing factors on both pellet durability index (PDI) and pelleting energy consumption, measured in kilowatt hours per ton (kWh/ton). Seven different factors, including ground corn particle size, added fat level, inclusion of distillers dried grains with solubles (DDGS), feed rate, steam conditioning temperature, conditioner retention time, and pellet die thickness (L:D ratio) were examined. Each factor was evaluated at two levels, and treatments were developed in order that all factor to factor comparisons could be made. Pellet samples were analyzed according to the standard method as described in ASAE S269.4, a modification of this method, and by using the NHP100 pellet tester set to each of its four testing intervals (30, 60, 90, and 120 seconds). The standard method was found to provide the most consistent and repeatable determinations of pellet durability, and was found to correlate well with the modified method, as well as with the NHP100 results at 30 and 60 seconds. Physical attributes of feed pellets, such as pellet hardness, bulk density, and moisture content were found to have significant, but weak correlations with pellet quality. Pellet quality was found to be significantly influenced by all factors other than ground corn particle size and feed rate. Higher fat level, lower conditioning temperature, and the thinner pellet die most significantly lowered pellet quality, with increasing effect respectively. A regression model was developed that was able to predict pellet durability within an average of 1.1 PDI. Pelleting energy consumption was found to be significantly influenced by all seven factors, with the higher fat level, thinner pellet die, and higher conditioning temperature most improving efficiency, with increasing effect respectively. A regression model was developed that was able to predict energy consumption within an average of 0.3 kWh/ton. The successful creation of regression equations demonstrates that there is potential for modeling and optimizing pellet quality and energy consumption within a pelleting operation.

Master of Agribusiness / Department of Agricultural Economics / Christine Wilson / The objective of this thesis is to examine the opportunity cost, both financial and efficiency, of inbound railcars of wheat that are not optimally loaded and shipped to ConAgra Mills’ facilities. In performing an analysis of data showing actual versus optimal weights, a cost will be assigned to determine how much “dead freight” or extra freight is being paid to railroads for space not utilized. Throughout the analysis, it can be determined which shippers are lacking efficiencies in loading as well as those who are meeting ConAgra Mills’ expectations. To accomplish this objective, data were extracted from various sources for an entire fiscal year and 22,351 data observations were analyzed. The information was specific to both individual railcars as well as the shipments as a whole. These data points were analyzed in two ways, financial and capacity/efficiency. Financially, a cost was assigned to each railcar that was under the railcar’s goal weight. From a capacity perspective, railcars were analyzed on a shipment basis to indicate if equipment could be saved by more efficient loading. The study determined that savings could be found in every situation analyzed. It was determined that in addition to inbound shipments from outside shippers, inter-mill shipments between ConAgra Mills facilities were affected by loading inefficiencies. There could be an opportunity for further analysis to determine the full scope of savings beyond the limitations of this study. The main limitation of this thesis was the primary source of data.

Master of Agribusiness / Department of Agricultural Economics / Kevin Dhuyvetter / This thesis was commissioned by Cooperative Producers, Inc. (CPI) of Hastings, Nebraska in order to better understand the preferences and uses of precision agriculture by customers within the company’s trade territory. With the rapid increase of precision agriculture (hardware, software, services, etc.) it is necessary to get a better understanding of what drives growers to adopt and implement precision agriculture practices. A paper survey was sent out in CPI’s monthly statements to patrons that also included instructions to be able to fill out an online survey if that was preferred. From that offering there were a total of 114 responses providing data from which several technology adoption models were estimated. Based on prior experience with precision agriculture and the development of services offered to growers, it is hypothesized that there are three primary variables influencing a grower’s decision to adopt precision agriculture. If the operation is managed by a younger grower (<40 years old), farms with a larger number of acres, and if a high percent of the operation’s acres are irrigated they will be more likely to adopt precision agriculture practices. The survey results generally revealed that younger farmers, larger farm size, and a higher percentage of irrigated acres did not increase the likelihood of utilizing precision agriculture. The questions asked in the survey were designed to provide information for the development of a tool that salespeople offering precision agriculture services could use to determine if a potential customer with be inclined to adopt and utilize precision agriculture. While some of the results were contrary to expectations they do offer insight into what type of customer adopts precision agriculture and a direction for CPI to move in order to maximize market penetration.

Master of Agribusiness / Department of Agricultural Economics / Michael Woolverton / To meet the demand of the 2007 Energy Bill will require a new approach to ethanol production in the United States. The question persists: how can the ethanol industry in the United States produce 21 billion gallons of ethanol from cellulosic sources? This challenge will require changes in the facilities currently manufacturing ethanol, the collection and storage methods to which the Midwestern farmer is accustomed, and a drastic change in farm production practices. Several different methods of cellulosic ethanol production are being examined. One such method is to change the focus from starch based ethanol to ethanol produced by harvest, collection, and manufacture from corn cobs. Research has included surveys, development of economic models, and focus group meetings to determine the feasibility of corn cobs as a viable raw material source for cellulosic ethanol. Findings indicate that: corn cob collection is feasible for the Midwestern farmer. According to the economic models presented in this thesis, Midwestern farmers can benefit economically from the collection of corn cobs. Further, the collection of corn cobs allows for current ethanol plants to be upgraded with new technology without major change in the manufacturing processes. The focus of this research was to determine which method of corn cob collection was preferable for Midwestern corn producers.

Master of Science / Department of Animal Sciences and Industry / Michael Tokach / In 3 experiments, 4,720 pigs were used to determine the effects of: 1) dietary fat and feeding duration on growth performance and fat quality in finishing pigs; or 2) a novel protease or 3) increasing levels of Zn amino acid complex (ZnAA) or ZnO on finishing pig performance. Experiment 1 tested the effects of feeding tallow, soybean oil, or a blend of the two for various feeding durations (d 0 to 42, 42 to 84, or 0 to 84). Overall, pigs fed added fat for the entire 84 d had improved G:F compared to those fed a control diet. Additionally, pigs fed additional fat for the entire study had improved ADG and G:F as well as increased d 84 BW compared to pigs fed additional fat for 42 d. Increasing the feeding duration of soybean oil lowered monounsaturated fatty acids and increased polyunsaturated fatty acid concentrations while these values remained relatively unchanged by the addition of tallow. There were feeding period by fat source interactions for fatty acid composition and iodine value for belly and backfat, but not jowl fat, indicating a longer turnover rate for jowl fat compared to belly or backfat. In Exp. 2, adding a protease to a nutrient deficient diet increased ADFI and tended to increase ADG compared to pigs fed a negative control diet. There were no differences observed in ADG, ADFI, or G:F between pigs fed a positive control diet, formulated to 90% of the pigs SID lysine requirement, and those fed a negative control diet plus the protease, which would suggest the release values attributed to the enzyme were accurate. In Exp. 3, supplementing additional Zn from either ZnAA or ZnO at 25, 50, or 75 ppm in finishing diets for commercial finishing pigs was evaluated. Overall, no differences were observed in ADFI, but a Zn source by level interaction was observed for ADG and G:F, as pigs fed increasing ZnO were observed to have similar performance, while pigs fed added levels of 25 and 50 ppm Zn from ZnAA had decreased performance compared to those fed the highest level of ZnAA.

Doctor of Philosophy / Department of Plant Pathology / Frank White / The genus Xanthomonas consists of bacterial species causing economically important plant diseases in major crops. In a wide variety of Xanthamonas species, the transcription activator-like (TAL) effectors (proteins) are synthesized and secreted into host cells, whereby they enter the plant nucleus. TAL effectors bind specific host gene promoters, inducing the expression of the targeted genes, which in some cases leads to either resistance or an enhanced state of disease susceptibility. The TAL effectors in individual Xanthomanas species and their targets in host plants have been characterized in relatively few cases. The premier example is the induction of any one member of a clade of sugar transporter genes in rice by TAL effectors of the bacterial blight pathogen X. oryzae pv. oryzae, where induction of the susceptibility (S) genes was shown to be required for the disease process. TAL effector genes are present in a wide variety of Xanthomonas species other than X. oryzae pv. oryzae. My dissertation focuses on the characterization of the TAL effectors in the citrus bacterial canker (CBC) and soybean bacterial pustule pathosystems. In CBC, CsLOB1 was identified as the S gene targeted by multiple major TAL effectors from CBC causal strains. Furthermore, another two members in family of citrus LBD family, although not identified as targets in the field, can serve as S genes in CBC. Initial analysis of bacterial pustule disease of soybean indicates that the TAL effector TAL2 of X. axonopodis pv. glycines is a virulence effector and associated with the expression of two candidate S genes, which encode a member of the ZF-HD transcription factors and a member of aluminum activated malate transporter family. These studies will enhance our understanding of plant-bacterial interactions and evolution of disease susceptibility, and also inform development of durable disease resistant crop varieties.